Capuchin monkeys (Cebus apella) learn to point with a laser

Pointing is an effective behavior for drawing attention or action to specific out-of-reach objects and locations. Monkeys do not spontaneously use a raised-arm point as do humans but may still be capable of pointing by other means. We provided 10 captive capuchin monkeys with a joystick-controlled laser pointer as a means of interacting with the distal environment. Subjects had previous experience with computerized joystick tasks, but required further training to use the same interface to control the laser. An important step was training the monkeys to attend to projected cursors and laser dots located off their computer monitor. Once the monkeys could control the laser pointer, we tested them with novel target locations and found that they moved the pointer to baited locations quickly and accurately while rarely passing through control locations [Binomial Sign Test, a=0.01]. Subsequently, subjects generalized their use of the laser to new 2D and 3D environments, demonstrating their ability to target edible and inedible objects up to 12 meters away and on different vertical and horizontal surfaces. This study demonstrates that monkeys can learn to use a novel tool to interact with the distal environment with great spatial specificity. The laser device allows direct comparison to pointing research in humans and apes, and opens new opportunities to study communicative, memorial and perceptual processes in non-human primates. Supported by HD38051 and HD056352.